Can I slowly increase generator input current

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jacko asked Feb 18, '19

Can I slowly increase generator input current

We have an off grid system that has a 20kVa generator, we’ve set maximum input current at 58amps which it can handle comfortably, but it doesn’t like going from nothing to this in such a short space of time from signal to start there is a small delay then the load comes on very quickly would be really good if you could set it to rise from a low input to your final input limit over a period of time that could be set say a minute or two? Think it would be good for the health of all components in the system? Is this possible?

Generator voltage

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technomadia commented · Feb 18, 2019 at 07:04 PM

It is not just for startup - I'd love to have the ability to drop the input current limit to cool down the generator too.

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Modifications Space

Node Red Space

Answer 1 · 2019-02-18T17:26:33Z

boekel answered · Feb 18, 2019 at 05:26 PM

There isn't a standard function for this in the Victron systems yet (hopefully it will be implemented in the feature), so we'll have to create a work around for now, like with using the 'ignore AC input' function.

I haven't tried it myself yet...but I think this should work to warm up the generator (for 4 minutes in this case)
slowly increasing the current is something I haven't tried yet, there are assistants to adjust charging current so there might be a way to accomplish this, albeit a little courser.

screenshot-2019-02-13-214213.png (25.0 KiB)

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jacko commented · Feb 18, 2019 at 05:40 PM

Thanks @Boekel this should be an improvement for the mean time hopfully a feature will be added in, it’s a bit harsh on the generator as it is.

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boekel ♦ jacko commented · Feb 18, 2019 at 05:47 PM

Yes I know, another trick I use is having a switch to decrease charging power, this is a manual switch, but as this client isn't using his generator more than a couple of times per season, it's good enough for now.

By the way, many generators have start/stop units that have a drive contact for a relay to engage after a warm-up time, if you use that (or just a timer starting when the generator starts) you could use one of the inputs of the Multi to set the 'ignore AC input' (or lower charge current, but existing AC-use will than load the genny) until the timer / generator control unit kicks in.

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petajoule boekel ♦ commented · Apr 04, 2020 at 01:24 PM

As we stumbled across a similar (same?) problem, and the answer here was "Dynamic current limiter" - isn't that the same answer here also?

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Daniël Boekel (Victron Energy Staff) ♦♦ petajoule commented · Apr 04, 2020 at 08:55 PM

Hi @PetaJoule

No, totally different, we're talking about a warm-up / cool-down period.

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Answer 2 · 2022-09-26T18:00:05Z

marc-heide answered · Sep 26, 2022 at 06:00 PM

Is there already a fix for this?

I would like to have an option to increase from 0 to full load over the time of 15 minutes.

So that i van apply the load slowly on the generator.

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Answer 3 · 2023-08-27T09:38:53Z

Tamz Rod answered · Aug 27, 2023 at 09:38 AM

Im new to Victron and playing around with node red so i have an idea to slowly adjust the input current limit after you started the generator.

Here is the code for ramp up. i shall made a code for ramp down too.

if (flow.get("ramp") >= 0 && flow.get("ramp") < 1 && flow.get("rampstate") == 1) {
    flow.set("ramp", flow.get("ramp") + 0.01);
    var ramp = flow.get("ramp");
    msg.payload = ramp * 25; // change 25 to your variable of max current draw
} else {
    flow.set("rampstate", 0);
    return null;
}

return msg;

screenshot-2023-08-27-173728.jpg (92.3 KiB)

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